A man accused of murdering his girlfriend had a ‘volatile’ relationship with her, a court heard.

Robert Trigg, from Worthing, is accused of the manslaughter of his partner Caroline Devlin and the murder of his girlfriend Susan Nicholson. He has denied both charges.

Miss Devlin, 35, was found dead in the bedroom of her home in Cranworth Road, Worthing, on Mothers’ Day – March, 26 – in 2006 while her daughter was cooking her breakfast. Her body was found with her head at the foot of the bed, and she was initially thought to have died of a brain aneurysm.

Miss Nicholson’s body was found on a sofa at her flat in Rowlands Road, Worthing, on April 17, 2011. Trigg claimed he accidentally smothered the 52-year-old by rolling on top of her in his sleep.

She told the court that Trigg and Miss Nicholson would drink alcohol ‘at least four days a week’.

When prosecutor Duncan Atkinson QC asked her to describe their relationship, she immediately said ‘volatile’.

She described Miss Nicholson as ‘lovely’, but said of Trigg: “Rob seemed to come across very violent. It was almost as if she was afraid of him.”

Miss Cooper said at its worst they would have blazing rows two or three times a week. She would hear things being thrown, screaming and shouting, and Miss Nicholson ‘begging’ Trigg ‘to get off her’ and ‘leave her alone’.

She added that she saw Miss Nicholson with physical injuries on four occasions, and would often call the police to report the fights.

She said: “As a young mum with an 11-month-old child, my main concern was my safety and my daughter’s safety’.

Today, the jury heard various statements from Trigg which he gave to police and at the inquests into the deaths of Miss Devlin and Miss Nicholson.

He said he met Miss Nicholson when they both attended rehab for alcohol dependency in July 2010, and started dating in November before he moved into her flat in December.

A month before she died, Trigg was cautioned by police for punching Miss Nicholson in the face after an argument.

The night before her death – Saturday, April 16 – Trigg said Susan asked him to ‘snuggle in’ and ‘crash here tonight’ with her on the sofa after an evening of drinking vodka.

He told the inquest into her death she was not ‘acting her bubbly self’ that day and that ‘it was almost as if she knew she was going to die’. He said Miss Nicholson sat him down and said to him: ‘do you know I love you more than I ever did before’, which he recalled as ‘odd’.

When he woke up at 2am on Sunday to use the toilet, he said she was very quiet. He told police: “I thought it was odd that she wasn’t snoring like she always snores but I didn’t think she was dead.”

At around 8am, Trigg said he jolted awake and realised his stomach was covering her face. He knew something was wrong: “She was still and hadn’t stirred all night. I saw her face was purple and thought ‘Oh my God, she’s dead’.”

He said he ‘panicked’ and went to a nearby corner shop to buy cigarettes – instead of calling 999.

He explained to police: “In my mind I was hoping she would wake up but inside I knew she was dead”.

Trigg then called his brother for advice before ringing Miss Cooper, telling her: ‘Sue is dead’.

He told the coroner: “I had to get someone to come and see her so I knew I wasn’t imagining it”.

Trigg was arrested by police on November 7 last year in relation to Miss Devlin and Miss Nicholson’s deaths.

The court heard how as he was driven to the police station, he said to officers ‘you do realise they have both passed away’ and ‘I’m shocked, I just thought all this was over’, before adding: ‘is it new medical evidence that has arisen?’.

On Tuesday, prosecutor Duncan Atkinson QC said it was ‘unlikely in the extreme’ that both Miss Devlin and Miss Nicholson could die of natural causes – as was found at inquests after their deaths – and in similar circumstances while sleeping with him, especially given his history of violence towards his partners.